JP5157410B2 - Steering device with telescopic shaft and telescopic shaft - Google Patents

Description

  The present invention relates to a steering device, and more particularly to a steering device having a telescopic shaft capable of transmitting rotational torque and relatively moving in an axial direction, for example, a telescopic shaft such as an intermediate shaft or a steering shaft.

  A telescopic shaft connected to the steering device so as to be able to transmit rotational torque and to be relatively movable in the axial direction is incorporated as an intermediate shaft, a steering shaft, or the like. That is, when the universal joint is fastened to the pinion shaft that meshes with the rack shaft of the steering gear, the intermediate shaft needs to have a telescopic function in order to be contracted once and then fitted to the pinion shaft and fastened.

  In addition, since the steering shaft needs to adjust the position of the steering wheel in the axial direction according to the physique and driving posture of the driver, an expansion / contraction function is required. As such a telescopic shaft, a telescopic shaft having a non-circular ball structure is generally used.

  The non-circulating ball structure intermediate shaft fits multiple balls between the male shaft side axial groove formed on the outer periphery of the male shaft and the female shaft side axial groove formed on the inner periphery of the female shaft. The ball rolls when the male shaft and the female shaft extend and contract so that the intermediate shaft can smoothly expand and contract.

  In such an intermediate shaft, the ball moves in the axial direction along the male shaft side axial groove of the male shaft while the ball rolls when the telescopic shaft expands and contracts. Therefore, the axial length of the male shaft side axial groove of the male shaft needs to be a length obtained by adding the axial movement length of the ball to the axial length for accommodating the ball.

  Due to the limited vehicle space and the required collapse stroke, the axial length of the intermediate shaft and the length of the fitting portion of the male shaft and female shaft constituting the intermediate shaft become a predetermined length. Determined. In addition, the axial length of the male shaft side axial groove is also determined to be a predetermined length depending on the expansion / contraction distance during normal use.

  When assembling the steering device to the vehicle body, the intermediate shaft is temporarily contracted beyond the expansion / contraction distance during normal use to fasten the universal joint to the pinion shaft that meshes with the rack shaft of the steering gear. It is necessary to fit and fasten.

  When the intermediate shaft is contracted beyond the expansion / contraction distance during normal use, the ball slides in the male shaft side axial groove and in the female shaft side axial groove. Therefore, the sliding resistance is increased, and a large force is required to shrink the intermediate shaft, which causes a problem that the assembling work becomes difficult.

  If the preload of the leaf spring that applies preload to the ball is reduced or the number of balls is reduced, the sliding resistance when the ball slides in the male shaft side axial groove and the female shaft side axial groove is reduced. it can. However, since the torsional rigidity and bending rigidity (bending rigidity in the direction perpendicular to the axis) of the intermediate shaft are reduced, the steering feeling of the steering device is lowered.

  In addition, since the bending rigidity is reduced, the cylindrical pin that transmits the rotational torque between the male shaft and the female shaft may come into contact with the axial groove on the female shaft side to generate a large hitting sound. is there.

  The power transmission shaft shown in Patent Document 1 eliminates the backlash of the fitting portion between the male shaft and the female shaft by a seal member provided with an end surface elastic seal portion. However, since the seal member of the power transmission shaft of Patent Document 1 has a structure that eliminates the backlash of the fitting portion of the male shaft and the female shaft by a soft elastic body, the effect of improving the bending rigidity in the direction perpendicular to the axis is achieved. There was a limit.

JP 2003-161331 A

  The present invention relates to a telescopic shaft and a telescopic shaft that have improved bending rigidity in a direction perpendicular to the axis in a steering device having a telescopic shaft and a telescopic shaft that have reduced sliding resistance when stretched beyond the range of expansion and contraction during normal use. It is an object of the present invention to provide a steering device including the above.

  The above problem is solved by the following means. That is, the first invention is a male shaft, a male shaft side axial groove formed on the outer periphery of the male shaft, and a female that is externally fitted to the male shaft so as to be capable of relative movement in the axial direction and to transmit rotational torque. A female shaft side axial groove formed on the inner periphery of the shaft and the female shaft at the same phase position as the male shaft side axial groove, and between the male shaft side axial groove and the female shaft side axial groove. A plurality of rolling elements inserted so as to be capable of rolling in the axial direction, a preload is applied between the rolling elements and the male shaft side axial groove, and between the rolling elements and the female shaft side axial groove. In the fitting portion between the biasing member, the male shaft and the female shaft, at least a pair of another male shaft side axial groove and a phase position different from the male shaft side axial groove and the female shaft side axial groove and Female shaft side axial groove shaped A cylindrical pin inserted into the at least one pair of another male shaft side axial groove and the female shaft side axial groove, and cannot move relative to the female shaft in the axial direction. A cylindrical member made of synthetic resin that suppresses relative displacement in the direction perpendicular to the axis between the inner periphery of the wiper mounting plate attached to the shaft end of the female shaft and the outer periphery of the male shaft. And a cylindrical member attached to the wiper mounting plate having an inclined surface on the inner periphery so as not to be relatively movable in the axial direction and having an inclined surface formed at the same inclination angle as the inclined surface. The telescopic shaft is characterized in that irregularities are formed on the inner periphery of the cylindrical member or the outer periphery of the male shaft.

The second invention is a telescopic shaft according to the first aspect of the invention, the male shaft is male intermediate shaft is a telescopic shaft, characterized in that the female shaft is female intermediate shaft.

Third invention is a steering device characterized by comprising a telescopic shaft of the first or second th one of the invention.

  In the telescopic shaft and the steering device of the present invention, the male shaft and the female shaft are press-fitted between the outer periphery of the male shaft and the inner periphery of the female shaft that are fitted to each other and are not relatively movable in the axial direction with respect to the female shaft. A cylindrical member that suppresses relative displacement in the direction perpendicular to the axis between the shaft and the shaft is provided. Accordingly, there is no fitting gap between the male shaft and the female shaft, and the bending rigidity in the direction perpendicular to the axis is large, so that the steering feeling of the steering device is improved.

  Further, in the telescopic shaft and the steering device of the present invention, irregularities are formed on the inner periphery of the cylindrical member or the outer periphery of the male shaft. Therefore, since the contact area between the inner periphery of the cylindrical member and the outer periphery of the male shaft is reduced, it is possible to achieve both reduction in sliding resistance of the telescopic shaft and improvement in bending rigidity in the direction perpendicular to the axis, and Since there is no need to manufacture parts such as members and male shafts with high accuracy, the manufacturing cost can be reduced.

  Hereinafter, Example 1 to Example 2 of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall side view of a steering apparatus according to the present invention, and is a partially sectional side view showing an embodiment applied to an electric power steering apparatus having a steering assisting portion. 2 is an enlarged view of the main part of FIG. 1 showing the steering apparatus according to the first embodiment of the present invention. FIG. 2 (1) is an enlarged vertical sectional view of an expansion / contraction part of the intermediate shaft, and FIG. It is an AA expanded sectional view of 2 (1).

  Fig. 3 (1) is an enlarged cross-sectional view of a portion P of Fig. 2 (2), and is an enlarged cross-sectional view of the cylindrical member before the male intermediate shaft is inserted, and Fig. 3 (2) is Fig. 2 (2). It is P section expanded sectional drawing of these, Comprising: It is an expanded sectional view of the cylindrical member and the male intermediate shaft of the state which inserted the male intermediate shaft. 4A is an enlarged cross-sectional view taken along line BB in FIG. 2A, and FIG. 4B is an enlarged cross-sectional view in the vicinity of the axial groove 54 in FIG.

  As shown in FIG. 1, the steering device of the present invention includes a steering shaft 12 on which a steering wheel 11 can be mounted on the rear side of the vehicle body (right side of FIG. 1), a steering column 13 inserted through the steering shaft 12, and the steering wheel. An assist device (steering assisting portion) 20 for applying assist torque to the shaft 12 and a steering gear connected to the front side of the vehicle body of the steering shaft 12 (left side in FIG. 1) via a rack / pinion mechanism (not shown). 30.

  The steering shaft 12 is spline-fitted between a female steering shaft 12A and a male steering shaft 12B so as to be able to transmit rotational torque and to be relatively movable in the axial direction. Therefore, when the female steering shaft 12A and the male steering shaft 12B collide, the spline fitting portion moves relative to each other so that the total length can be shortened.

  Further, the cylindrical steering column 13 inserted through the steering shaft 12 combines the outer column 13A and the inner column 13B so that they can be telescopically moved. It has a so-called collapsible structure in which the entire length is shortened while absorbing water.

  The vehicle body front side end portion of the inner column 13B is press-fitted and fixed to the vehicle body rear side end portion of the gear housing 21. Further, the front end portion of the male steering shaft 12B on the vehicle body is passed through the inside of the gear housing 21 and connected to the rear end portion of the assist device 20 on the rear side of the input shaft (not shown).

  The steering column 13 is supported by a support bracket 14 at a middle portion thereof on a part of the vehicle body 18 such as a lower surface of the dashboard. Further, a locking portion (not shown) is provided between the support bracket 14 and the vehicle body 18, and when an impact in a direction toward the front side of the vehicle body is applied to the support bracket 14, the support bracket 14 is locked to the locking bracket 14. It moves away from the vehicle and moves to the front side of the vehicle.

  The upper end portion of the gear housing 21 is also supported on a part of the vehicle body 18. In this embodiment, the height position of the steering wheel 11 and the longitudinal position of the vehicle body can be freely adjusted by providing a tilt mechanism and a telescopic mechanism. Such a tilt mechanism and a telescopic mechanism are well known in the art and are not characteristic features of the present invention, and thus detailed description thereof is omitted.

  The output shaft 23 protruding from the end face on the front side of the vehicle body of the gear housing 21 is connected to the rear end portion of the intermediate shaft 16 via the universal joint 15. Further, the input shaft 31 of the steering gear 30 is connected to the front end portion of the intermediate shaft 16 via another universal joint 17. The intermediate shaft 16 is fitted on the vehicle body front side of the male intermediate shaft (male shaft) 16A on the vehicle body rear side of the female intermediate shaft (female shaft) 16B, so that rotational torque can be transmitted and relative movement in the axial direction is possible. Is fitted.

  A pinion (not shown) is coupled to the input shaft 31. A rack (not shown) fitted in the steering gear 30 so as to be reciprocally slidable meshes with the pinion, and the rotation of the steering wheel 11 moves the tie rod 32 to steer a wheel (not shown).

  A case 261 of an electric motor 26 is fixed to the gear housing 21 of the assist device 20, and a worm is coupled to a rotating shaft (not shown) of the electric motor 26. A worm wheel (not shown) is attached to the output shaft 23, and the worm of the rotating shaft of the electric motor 26 is engaged with the worm wheel.

  A torque sensor (not shown) is provided around an intermediate portion of the axial length of the output shaft 23. The direction and magnitude of torque applied from the steering wheel 11 to the steering shaft 12 is detected by a torque sensor.

  The electric motor 26 is driven according to the detected value of the torque sensor, and auxiliary torque is generated in a predetermined direction in a predetermined direction on the output shaft 23 via a speed reduction mechanism composed of a worm and a worm wheel. The assist device 20 is not limited to an electric assist device, and may be a hydraulic assist device provided in the steering gear 30 or the like.

  FIGS. 2 to 4 show the connecting part of the telescopic shaft of Example 1 of the present invention, and shows an example applied to the connecting part of the male intermediate shaft 16A and the female intermediate shaft 16B of the intermediate shaft 16 of FIG.

  As shown in FIGS. 2 to 4, the vehicle rear side (right side of FIG. 2 (1)) of the female intermediate shaft (female shaft) 16B is the vehicle front side (FIG. 2 (1) of the male intermediate shaft (male shaft) 16A). ) On the left side). The female intermediate shaft 16B is formed in a hollow cylindrical shape, and an axial groove 41 (female shaft side axial groove) 41 having a substantially semicircular cross section at the axis perpendicular to the inner periphery of the inner diameter hole 40 has a telescopic stroke. Six pieces are formed at equal intervals (60-degree intervals) over the entire length.

  The front side of the vehicle body of the male intermediate shaft 16A is formed in a solid cylindrical shape. From the front side of the vehicle body, a large diameter shaft portion 50 having a large diameter and a diameter smaller than that of the large diameter shaft portion 50 are formed. The small-diameter shaft portions 51 are formed in this order.

  On the outer periphery of the large-diameter shaft portion 50 of the male intermediate shaft 16A, three axial grooves (male shaft-side axial grooves) 52 having a substantially semicircular cross-section are substantially axial directions of the large-diameter shaft portion 50. It is formed at equal intervals (120 degree intervals) over the entire length.

  A solid cylindrical pin as a rotational torque transmitting member is formed in a cylindrical space formed by the three axial grooves 52 of the male intermediate shaft 16A and the three axial grooves 41 of the female intermediate shaft 16B. (Needle roller) 53 is inserted. The outer diameter of the cylindrical pin 53 is slightly smaller than the inner diameter of the cylindrical space formed by the axial groove 52 of the male intermediate shaft 16A and the axial groove 41 of the female intermediate shaft 16B. ing.

  On the outer periphery of the large-diameter shaft portion 50 of the male intermediate shaft 16A, there are three axial grooves (male shaft side axial grooves) having a substantially trapezoidal cross section at a midpoint between adjacent axial grooves 52, 52. 54 are formed at equal intervals (120 degree intervals) over substantially the entire axial length of the large-diameter shaft portion 50.

  A plurality of spherical balls (three balls) as rolling elements are formed in a space formed by the three substantially trapezoidal axial grooves 54 and the three axial grooves 41 in the same phase of the female intermediate shaft 16B. 55 are respectively inserted.

  In the embodiment of the present invention, when the number of the balls 55 is reduced from five normally used to three, when the intermediate shaft 16 is contracted beyond the expansion / contraction distance during normal use, the axial groove 54 and the shaft The sliding resistance when the ball 55 slides in the directional groove 41 is reduced so that the assembling work can be performed easily.

  Further, a leaf spring (biasing member) 56 as a preload applying member is inserted between the three substantially trapezoidal axial grooves 54 and the ball 55. As shown in detail in FIG. 4 (2), the axial groove 54 is composed of a bottom wall 541 wider than the diameter of the ball 55 and side walls 542 and 542 extending upward in a V shape from both ends of the bottom wall 541. It is configured. The leaf spring 56 has substantially the same length as the axial length of the axial groove 54 and is elastically deformed and inserted between the axial groove 54 and the ball 55.

  The plate spring 56 includes a bottom plate 561 that contacts the bottom wall 541 of the axial groove 54, and side plates 562 and 562 that extend upward in a V shape from both ends of the bottom plate 561 and respectively contact the ball 55. . Further, folded portions 563 and 563 that are bent outward in an arc shape are formed at the upper ends of the side plates 562 and 562, and contact portions 564 and 564 that extend downward from the folded portion 563 toward the bottom wall 541 are formed, The contact portion 564 is in contact with the side wall 542 of the axial groove 54.

  The side plates 562 and 562, the folded portions 563 and 563, and the contact portions 564 and 564 of the leaf spring 56 are elastically deformed to absorb the play between the ball 55 and the axial groove 54. There is a minute gap between the cylindrical pin 53 and the axial groove 41 and the axial groove 52. The cylindrical pin 53 comes into contact with the axial groove 41 and the axial groove 52 when the female intermediate shaft 16B and the male intermediate shaft 16A are relatively displaced by a slight angle in the rotational direction.

  The leaf spring 56 is inserted in a compressed state between the ball 55 and the substantially trapezoidal axial groove 54, and the elasticity of the leaf spring 56 is inserted between the axial groove 54, the ball 55, and the axial groove 41. An urging force (predetermined preload) due to deformation is applied.

  In the embodiment of the present invention, as described above, the number of the balls 55 is reduced, and the diameter of the balls 55 is slightly reduced so that when the intermediate shaft 16 is contracted beyond the expansion / contraction distance during normal use, the axial direction The sliding resistance when the ball 55 slides in the groove 54 and the axial groove 41 is reduced so that the assembling work can be performed easily.

  As another method, by reducing the urging force of the leaf spring 56 by reducing the plate thickness of the leaf spring 56, the ball 55 slides in the axial groove 54 and the axial groove 41. The sliding resistance may be reduced to facilitate the assembly work.

  A disc-shaped washer 58, a disc-shaped spring plate 59, and a disc-shaped washer 60 are arranged in this order from the rear side of the vehicle body on the small-diameter shaft portion 57 formed at the front end of the large-diameter portion 50 of the male intermediate shaft 16A. It is externally fitted. The front end of the vehicle body of the small-diameter shaft portion 57 is crimped, and the spring plate 59 applies a biasing force to the vehicle body rear side (right side in FIG. 2A) to the vehicle body rear side washer 58.

  The end surface of the washer 58 on the vehicle body rear side is in contact with the vehicle body front end of the cylindrical pin 53 and has a function as a regulating member that regulates the axial movement of the cylindrical pin 53. A wall perpendicular to the axis of the male intermediate shaft 16 </ b> A is formed at the vehicle body rear end of the axial groove 52, and receives the vehicle body rear end of the cylindrical pin 53. Moreover, the vehicle body rear end and the vehicle body front end of the cylindrical pin 53 are crowned or tapered, and are reduced in diameter toward the end side.

  A small-diameter cylindrical portion 44 is formed at the vehicle body rear end of the female intermediate shaft 16B, and an inner periphery 421 of a thin cylindrical wiper mounting plate 42 is press-fitted into an outer periphery 441 of the small-diameter cylindrical portion 44. The wiper mounting plate 42 extends in a cylindrical shape toward the rear of the vehicle body from the rear surface end surface 442 of the small-diameter cylindrical portion 44, and is then bent into an L shape toward the axial center of the male intermediate shaft 16A. Is formed.

  A wiper 43 made of rubber or the like is fixed to the bent portion 422. The wiper 43 slides on the outer periphery 511 of the small-diameter shaft portion 51, and dust is generated in the fitting portion between the female intermediate shaft 16B and the male intermediate shaft 16A. Prevents intrusion.

  A cylindrical tubular member 61 is press-fitted between the inner periphery 421 of the wiper mounting plate 42 and the outer periphery 511 of the small diameter shaft portion 51. Since both the front and rear ends of the cylindrical member 61 in the axial direction are sandwiched between the vehicle body rear side end surface 442 of the small diameter cylindrical portion 44 and the bent portion 422 of the wiper mounting plate 42, the cylindrical member 61 is a female intermediate It is attached so as not to move relative to the shaft 16B in the axial direction.

  The wiper mounting plate 42 is manufactured by pressing an iron thin plate with a press. After the wiper 43 and the cylindrical member 61 are press-fitted into the wiper mounting plate 42, the front end of the vehicle body on the inner periphery 421 of the wiper mounting plate 42 is formed. Press fit into the outer periphery 441 of the small diameter cylindrical portion 44.

  As shown in FIGS. 2 (2) and 3 (1), serrated irregularities 62 are formed on the inner circumference of the cylindrical member 61 at equal pitches over the entire circumference. The convex vertex 621 of the serrated irregularities 62 protrudes to the axial center side of the small-diameter shaft portion 51 from the outer periphery 511 of the small-diameter shaft portion 51, and the concave vertex 622 projects outward from the outer periphery 511 of the small-diameter shaft portion 51. Yes.

  The serrated irregularities 62 are formed over the entire inner circumference of the cylindrical member 61, but may be formed on a part of the inner circumference of the cylindrical member 61. Further, the serrated irregularities 62 are formed at an equal pitch on the inner periphery of the cylindrical member 61, but may be formed at an unequal pitch.

  The material of the cylindrical member 61 is preferably molded from a synthetic resin such as tetrafluoroethylene resin (PTFE) or polyamide (PA), which has a small friction coefficient, is self-lubricating, and has excellent wear resistance.

  Therefore, as shown in FIG. 3B, when the outer periphery 511 of the small-diameter shaft portion 51 is fitted to the cylindrical member 61, the convex portion vertex 621 is deformed and comes into contact with the outer periphery 511 of the small-diameter shaft portion 51. Since the apex 622 does not contact the outer periphery 511 of the small diameter shaft portion 51, the contact area between the inner periphery of the cylindrical member 61 and the outer periphery 511 of the small diameter shaft portion 51 decreases.

  Therefore, the ball 55 slipped in the axial groove 54 and the axial groove 41 when the intermediate shaft 16 was contracted beyond the sliding resistance when adjusting the telescopic position during normal use and the expansion / contraction distance during normal use. Since the sliding resistance at the time becomes small, telescopic position adjustment and assembly work can be performed easily.

  Further, when the outer periphery 511 of the small diameter shaft portion 51 is fitted to the cylindrical member 61, the convex portion vertex 621 is deformed following the outer periphery 511 of the small diameter shaft portion 51, and the small diameter shaft portion 51 is formed on the inner periphery of the cylindrical member 61. The outer periphery 511 can be smoothly press-fitted. Therefore, it is possible to achieve both a reduction in sliding resistance of the intermediate shaft 16 and an improvement in bending rigidity in the direction perpendicular to the axis without increasing the dimensional accuracy of components such as the cylindrical member 61 and the small-diameter shaft portion 51. Manufacturing costs can be reduced.

  When the male intermediate shaft 16A is moved in the left-right direction in FIG. 2 with respect to the female intermediate shaft 16B after the assembly operation of the steering device to the vehicle body 18 is completed, the ball 55 rotates and the ball 55 is inserted into the axial groove 54. While rolling along, the vehicle moves rearward (rightward) or forward (leftward).

  When the rotational torque between the male intermediate shaft 16A and the female intermediate shaft 16B is equal to or lower than a predetermined torque, the axial groove 54 of the male intermediate shaft 16A and the axial direction of the female intermediate shaft 16B are interposed via the leaf spring 56 and the ball 55. A rotational torque is transmitted between the grooves 41.

  When rotational torque (input torque) is applied between the male intermediate shaft 16A and the female intermediate shaft 16B, and the rotational torque reaches a predetermined torque, the amount of elastic deformation of the leaf spring 56 is reduced by the cylindrical pin 53 and the axial groove 41. And the amount of the minute gap between the axial grooves 52 is the same. As a result, the outer periphery of the cylindrical pin 53 is simultaneously brought into contact with the axial groove 41 and the axial groove 52 to transmit rotational torque.

  When bending stress in the direction perpendicular to the axis acts on the intermediate shaft 16, the outer periphery 511 of the small-diameter shaft portion 51 is press-fitted into the inner periphery of the cylindrical member 61, and therefore, between the male intermediate shaft 16A and the female intermediate shaft 16B. Since there is no fitting gap and the bending rigidity in the direction perpendicular to the axis is large, the steering feeling of the steering device is improved.

  Next, a second embodiment of the present invention will be described. FIG. 5 is an enlarged view of the main part of FIG. 1 showing the steering apparatus according to the second embodiment of the present invention, and is an enlarged vertical sectional view of the telescopic part of the intermediate shaft. In the following description, only structural portions and operations different from those of the first embodiment will be described, and overlapping descriptions will be omitted. The same parts as those in the first embodiment will be described with the same numbers.

  The second embodiment is a modification of the first embodiment, in which a cylindrical pin is used instead of the ball 55. That is, as shown in FIG. 5, a solid circle is formed in the space formed by the three substantially trapezoidal axial grooves 54 into which the balls 55 are inserted and the three axial grooves 41 in the first embodiment. Columnar pins (needle rollers) 63 are respectively inserted.

  Further, a leaf spring (biasing member) 56 as a preload applying member is inserted between the three substantially trapezoidal axial grooves 54 and the cylindrical pin 63. The leaf spring 56 has substantially the same length as the axial length of the axial groove 54 and is elastically deformed and inserted between the axial groove 54 and the cylindrical pin 63.

  The leaf spring 56 is inserted in a compressed state between the cylindrical pin 63 and the substantially trapezoidal axial groove 54, and between the axial groove 54, the cylindrical pin 63, and the axial groove 41, An urging force (predetermined preload) due to elastic deformation of the spring 56 is applied.

  The cylindrical pin 63 is formed such that its axial length (the length in the left-right direction in FIG. 5) is shorter than the total axial length of the axial groove 54. In the embodiment of the present invention, the diameter of the cylindrical pin 63 is slightly smaller. As a result, the intermediate shaft 16 is contracted beyond the expansion / contraction distance during normal use, and when the rear end of the cylindrical pin 63 comes into contact with the rear end of the axial groove 54, the cylindrical pin within the axial groove 41. The sliding resistance when 63 slides is reduced so that the assembly work can be performed easily.

  The shape of the cylindrical member 61 press-fitted into the space between the inner periphery 421 of the wiper attachment plate 42 and the outer periphery 511 of the small-diameter shaft portion 51 press-fitted into the vehicle body rear side end of the female intermediate shaft 16B. These are the same as in Example 1.

  When the male intermediate shaft 16A is moved in the left-right direction in FIG. 5 with respect to the female intermediate shaft 16B after the assembly operation of the steering device to the vehicle body 18 is completed, the cylindrical pin 63 slides along the axial groove 41. However, it moves to the vehicle body rear side (right direction) or the vehicle body front side (left direction).

  When the rotational torque between the male intermediate shaft 16A and the female intermediate shaft 16B is equal to or lower than a predetermined torque, the axial groove 54 of the male intermediate shaft 16A and the female intermediate shaft 16B are interposed via the leaf spring 56 and the cylindrical pin 63. A rotational torque is transmitted to and from the axial groove 41.

  When rotational torque (input torque) is applied between the male intermediate shaft 16A and the female intermediate shaft 16B, and the rotational torque reaches a predetermined torque, the amount of elastic deformation of the leaf spring 56 is reduced to the torque transmitting columnar pin 53. This is the same as the minute gap between the axial groove 41 and the axial groove 52. As a result, the outer periphery of the cylindrical pin 53 is simultaneously brought into contact with the axial groove 41 and the axial groove 52 to transmit rotational torque.

  When bending stress in the direction perpendicular to the axis acts on the intermediate shaft 16, the outer periphery 511 of the small-diameter shaft portion 51 is press-fitted into the inner periphery of the cylindrical member 61, and therefore, between the male intermediate shaft 16A and the female intermediate shaft 16B. Since there is no fitting gap and the bending rigidity in the direction perpendicular to the axis is large, the steering feeling of the steering device is improved.

  Next, a third embodiment of the present invention will be described. FIG. 6 is an enlarged view of the main part of FIG. 1 showing the steering apparatus according to the third embodiment of the present invention, and is an enlarged vertical sectional view of the telescopic part of the intermediate shaft. FIG. 7 is an enlarged perspective view of the vicinity of the cylindrical member according to the third embodiment of the present invention. FIG. 8 is a view corresponding to FIG. 6 showing a modification of the third embodiment of the present invention. In the following description, only structural portions and operations different from the above embodiment will be described, and redundant description will be omitted. Further, the same parts as those in the above embodiment will be described with the same numbers.

  The third embodiment is an example in which a spring ring that always applies a preload to the tubular member 61 is inserted in the outer periphery of the tubular member 61. That is, as shown in FIG. 6, the inner periphery 421 of the wiper mounting plate 42 having the same shape as that of the above embodiment is press-fitted into the outer periphery 441 of the small-diameter cylindrical portion 44 at the vehicle body rear side end portion of the female intermediate shaft 16B. .

  A cylindrical tubular member 61 is press-fitted between the inner periphery 421 of the wiper mounting plate 42 and the outer periphery 511 of the small diameter shaft portion 51 via a spring ring 64.

  Since both the front and rear ends of the cylindrical member 61 and the spring ring 64 in the axial direction are sandwiched between the vehicle body rear side end surface 442 of the small diameter cylindrical portion 44 and the bent portion 422 of the wiper mounting plate 42, the cylindrical member 61, The spring ring 64 is attached so as not to move relative to the female intermediate shaft 16B in the axial direction.

  The wiper mounting plate 42 is manufactured by pressing an iron thin plate with a press. After the wiper 43, the cylindrical member 61 and the spring ring 64 are press-fitted into the wiper mounting plate 42, the front of the vehicle body on the inner periphery 421 of the wiper mounting plate 42 is obtained. The end is press-fitted into the outer periphery 441 of the small diameter cylindrical portion 44.

  As shown in FIG. 7, convex portions 641 are formed at an equal pitch over the entire circumference of the spring ring 64 in which an iron thin plate is formed in an annular shape, and the convex portions 641 are the inner circumference 421 of the wiper mounting plate 42. The spring ring 64 is reduced in diameter, and the outer periphery of the cylindrical member 61 is tightened.

  Further, as shown in FIG. 7, a slit 611 is formed in the tubular member 61 over the entire length in the axial direction, and when the outer periphery of the tubular member 61 is tightened by the spring ring 64, the tubular member 61 is reduced in diameter. The inner periphery of the cylindrical member 61 contacts the outer periphery 511 of the small diameter shaft portion 51. Instead of the slits 611, serrated irregularities 62 may be formed on the inner periphery of the cylindrical member 61 at an equal pitch over the entire periphery, as in the first embodiment.

  Therefore, when the outer periphery 511 of the small-diameter shaft portion 51 is fitted to the tubular member 61, the spring ring 64 tightens the outer periphery of the tubular member 61, the tubular member 61 is reduced in diameter, and the inner periphery of the tubular member 61 is reduced in diameter. It contacts the outer periphery 511 of the shaft portion 51.

  When the intermediate shaft 16 is used by being incorporated in the vehicle body, the inner periphery of the cylindrical member 61 is worn. However, the spring ring 64 is elastically deformed and reduced in diameter by the amount of wear, and the outer periphery of the cylindrical member 61 is tightened. As a result, the diameter of the cylindrical member 61 is reduced, and the inner periphery of the cylindrical member 61 is kept in contact with the outer periphery 511 of the small diameter shaft portion 51.

  Therefore, the contact state between the inner periphery of the cylindrical member 61 and the outer periphery 511 of the small-diameter shaft portion 51 is maintained for a long time, there is no fitting gap between the male intermediate shaft 16A and the female intermediate shaft 16B, and the direction perpendicular to the axis Since the bending rigidity of the steering device is large, the steering feeling of the steering device is improved.

  FIG. 8 is a view corresponding to FIG. 6 showing a modification of the third embodiment of the present invention. In the example of FIG. 8, instead of the inner periphery 421 of the wiper mounting plate 42, a cylindrical shape is interposed between the inner periphery 443 of the small diameter cylindrical portion 44 of the female intermediate shaft 16 </ b> B and the outer periphery 511 of the small diameter shaft portion 51 via the spring ring 64. The member 61 is press-fitted.

  Next, a fourth embodiment of the present invention will be described. FIG. 9 is an enlarged perspective view showing a wiper mounting plate of Embodiment 4 of the present invention. In the following description, only structural portions and operations different from the above embodiment will be described, and redundant description will be omitted. Further, the same parts as those in the above embodiment will be described with the same numbers.

  As shown in FIG. 9, slits 423 are formed on the wiper mounting plate 42 of the fourth embodiment at an equal pitch over the entire circumference. The slit 423 elastically deforms the wiper mounting plate 42, reduces the diameter of the inner periphery 421 of the wiper mounting plate 42, and tightens the outer periphery of the cylindrical member 61.

  Therefore, even if the spring ring 64 of the third embodiment is not provided, the wiper mounting plate 42 is elastically deformed by the amount of wear on the inner periphery of the tubular member 61 and the outer periphery of the tubular member 61 is tightened. As a result, the diameter of the cylindrical member 61 is reduced, and the inner periphery of the cylindrical member 61 can be kept in contact with the outer periphery 511 of the small diameter shaft portion 51.

  Next, a fifth embodiment of the present invention will be described. FIG. 10 is an enlarged view of the main part of FIG. 1 showing the steering apparatus according to the fifth embodiment of the present invention, and is an enlarged vertical sectional view of the telescopic part of the intermediate shaft. In the following description, only structural portions and operations different from the above embodiment will be described, and redundant description will be omitted. Further, the same parts as those in the above embodiment will be described with the same numbers.

  As shown in FIG. 10, an inclined surface 424 is formed at the rear end of the vehicle body on the inner periphery 421 of the wiper mounting plate 42 of the fifth embodiment. The inclined surface 424 is inclined in a direction in which the vehicle body rear side of the inclined surface 424 approaches the axis of the male intermediate shaft 16A. An inclined surface 612 is also formed at the rear end of the tubular member 61 that is press-fitted between the inner periphery 421 of the wiper mounting plate 42 and the outer periphery 511 of the small-diameter shaft portion 51. The inclined surface 612 is formed at the same inclination angle as the inclined surface 424 and is in contact with the inclined surface 424.

  Therefore, the inclined surface 424 presses the inclined surface 612 by the amount of wear on the inner periphery of the cylindrical member 61, the cylindrical member 61 moves inward in the radial direction, and the inner periphery of the cylindrical member 61 is the small-diameter shaft portion 51. The contact state with the outer periphery 511 can be maintained. The slit 423 of the fourth embodiment may be formed in the wiper mounting plate 42, and the wiper mounting plate 42 may be elastically deformed by the slit 423 so that the inner circumference 421 of the wiper mounting plate 42 is reduced in diameter.

  In the above embodiment, the serrated irregularities 62 are formed on the inner circumference of the cylindrical member 61, but the serrated irregularities may be formed on the outer circumference 511 of the small diameter shaft portion 51 of the male intermediate shaft 16A. In the above embodiment, the cylindrical member 61 is press-fitted into the inner periphery 421 of the wiper mounting plate 42 formed separately from the female intermediate shaft 16B. However, the cylindrical member 61 is directly cylindrical on the inner periphery of the female intermediate shaft 16B. The member 61 may be press-fitted.

  Although the said Example demonstrated the example which applied this invention to the intermediate shaft 16, it can apply to the arbitrary expansion-contraction shafts which comprise steering apparatuses, such as the steering shaft 12. FIG. Further, in the above embodiment, the vehicle rear side of the female intermediate shaft 16B is externally fitted and connected to the vehicle front side of the male intermediate shaft 16A, but the vehicle body of the male intermediate shaft 16A is connected to the vehicle front side of the female intermediate shaft 16B. The rear side may be fitted and connected.

BRIEF DESCRIPTION OF THE DRAWINGS It is the side view which showed the whole steering apparatus of this invention, and was partially cut, Comprising: The Example applied to the electric power steering apparatus is shown. It is an enlarged view of the principal part of FIG. 1 which shows the steering apparatus of Example 1 of this invention, Comprising: (1) is an expanded longitudinal cross-sectional view of the expansion-contraction part of an intermediate shaft, (2) is AA expansion of (1). It is sectional drawing. (1) is an enlarged cross-sectional view of the P part in FIG. 2 (2), and is an enlarged cross-sectional view of the cylindrical member before the male intermediate shaft is inserted, and (2) is an enlarged view of the P part of FIG. 2 (2). It is sectional drawing, Comprising: It is an expanded sectional view of the cylindrical member and the male intermediate shaft of the state which inserted the male intermediate shaft. (1) is an BB enlarged sectional view of FIG. 2 (1), and (2) is an enlarged sectional view of the vicinity of the axial groove 54 of FIG. 4 (1). It is an enlarged view of the principal part of FIG. 1 which shows the steering apparatus of Example 2 of this invention, Comprising: It is an expanded longitudinal cross-sectional view of the expansion-contraction part of an intermediate shaft. It is an enlarged view of the principal part of FIG. 1 which shows the steering apparatus of Example 3 of this invention, Comprising: It is an enlarged vertical sectional view of the expansion-contraction part of an intermediate shaft. It is an expansion perspective view of the cylindrical member vicinity of Example 3 of this invention. FIG. 7 is a view corresponding to FIG. 6 showing a modification of the third embodiment of the present invention. It is an expansion perspective view which shows the wiper attachment plate of Example 4 of this invention. It is an enlarged view of the principal part of FIG. 1 which shows the steering apparatus of Example 5 of this invention, Comprising: It is an expanded longitudinal cross-sectional view of the expansion-contraction part of an intermediate shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Steering wheel 12 Steering shaft 12A Female steering shaft 12B Male steering shaft 13 Steering column 13A Outer column 13B Inner column 14 Support bracket 15 Universal joint 16 Intermediate shaft 16A Male intermediate shaft 16B Female intermediate shaft 17 Universal joint 18 Car body 20 Assist device 21 Gear Housing 23 Output shaft 26 Electric motor 261 Case 30 Steering gear 31 Input shaft 32 Tie rod 40 Inner diameter hole 41 Axial groove (female shaft side axial groove)
42 Wiper mounting plate 421 Inner circumference 422 Bending portion 423 Slit 424 Inclined surface 43 Wiper 44 Small diameter cylindrical portion 441 Outer periphery 442 Car body rear side end surface 443 Inner periphery 50 Large diameter shaft portion 51 Small diameter shaft portion 511 Outer periphery 52 Axial groove (male shaft side) Axial groove)
53 Cylindrical pin (Needle roller)
54 Axial groove (male shaft side axial groove)
541 Bottom wall 542 Side wall 55 Ball 56 Leaf spring 561 Bottom plate 562 Side plate 563 Folding portion 564 Abutting portion 57 Small diameter shaft portion 58 Washer 59 Spring plate 60 Washer 61 Cylindrical member 611 Slit 612 Inclined surface 62 Sawtooth-shaped unevenness 621 Convex portion 621 622 Concave vertex 63 Cylindrical pin 64 Spring ring 641 Convex part

Claims (3)

Male shaft,
Male shaft side axial groove formed on the outer periphery of the male shaft,
A female shaft that is externally fitted to the male shaft so as to be relatively movable in the axial direction and capable of transmitting rotational torque;
On the inner periphery of the female shaft, the female shaft side axial groove formed at the same phase position as the male shaft side axial groove,
A plurality of rolling elements inserted between the male shaft side axial groove and the female shaft side axial groove so as to be capable of rolling in the axial direction;
An urging member for applying a preload between the rolling element and the male shaft side axial groove, and between the rolling element and the female shaft side axial groove;
In the fitting portion between the male shaft and the female shaft, at least a pair of another male shaft side axial groove and a female shaft side shaft at a phase position different from the male shaft side axial groove and the female shaft side axial groove. Directional grooves are formed, and cylindrical pins inserted into the at least one other pair of male shaft side axial grooves and female shaft side axial grooves,
A cylindrical member made of a synthetic resin that is incapable of relative movement in the axial direction with respect to the female shaft and suppresses relative displacement in the direction perpendicular to the axis between the male shaft and the female shaft, and is attached to the axial end of the female shaft. Press-fitted between the inner periphery of the attached wiper attachment plate and the outer periphery of the male shaft, and attached to the wiper attachment plate having an inclined surface on the inner periphery, and formed at the same inclination angle as the inclined surface. A telescopic shaft, comprising: a cylindrical member having an inclined surface; and an unevenness formed on the inner periphery of the cylindrical member or the outer periphery of the male shaft. The telescopic shaft according to claim 1,
The male shaft is a male intermediate shaft,
The telescopic shaft, wherein the female shaft is a female intermediate shaft. A steering apparatus comprising the telescopic shaft according to claim 1.

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